1. Field of the Invention
The present invention relates to a method for the cleaning and disinfection of articles and equipment such as vessels and conveyor belts in the brewing industry by applying an aqueous composition to or at the places to be cleaned.
2. Description of the Related Art
The cleaning and disinfection of articles of the type mentioned at the outset having relatively smooth inner surfaces which are used, e.g., in the area of packaging or charging foods or other perishable products is relatively problematical. It is not always possible, in the time available, to ensure a sufficiently long time of action of the corresponding components. This becomes disturbingly noticeable, e.g., very frequently in the brewing industry, in particular in the packaging area, if for example so-called beer spoilage organisms, which can multiply highly intensively under current conditions of low-oxygen packaging, are to be reliably eliminated. It has been shown, for example, that beer spoilage organisms such as Pectinatus cerevisiiphilus or Megasphaera cerevisiae have considerable resistance to the cleaning and disinfection agents currently used.
Although an absolutely satisfactory disinfection can be achieved with known disinfectants such as chlorine bleach solution, the use of this agent demonstrates undesirable effects on technical installations made of stainless steel such as pipes and the like as a consequence of corrosion phenomena. The legal restriction that waste water be allowed to contain no more than 0.2 mg of free chlorine per litre of waste water is likewise a disadvantage. At higher concentrations a separate treatment for waste water would have to be performed in order to decrease the concentration of equivalents of free chlorine below the prescribed value. Finally, it is known that chlorine bleach solution has a tendency to form so-called haloforms with organic compounds. These compounds are considered to be cancerogenic and are therefore also hazardous from the health aspect.
The disinfecting action of hydrogen peroxide or peracetic acid is known from first principles.
In order to ensure reliable disinfection at the concentrations of disinfectants conventionally used, a long contact time is required with such agents. However, this cannot be easily ensured as a result of the necessary high throughput of articles to be disinfected, in particular those having vertical relatively smooth surfaces.
Furthermore, the cleaning action of such a solution is not satisfactory.
EP-A-0,404,293 describes a thickened aqueous cleaning solution which has a bleaching action. The cleaning solution, in addition to the polymer used as thickener and a fluorescent brightener, contains H.sub.2 O.sub.2 and defined amine oxides.
GB-A-2,255,507 likewise describes thickened, aqueous cleaning solutions which have a bleaching action. The solutions, in addition to a peroxo compound contain a dinonylphenylethoxylate as a thickener together with a micell-forming surfactant which can be an amine oxide.
DE-A-3,800,337 discloses an acidic cleaning agent for aluminum which has a pH of at most 2 and has, as constituents, a strong mineral acid selected from the group consisting of sulfuric acid, phosphoric acid and nitric acid, at least one peroxo compound and, as surfactant, an alkyldimethylamine oxide.
EP-A-253,676 discloses an aqueous, thickened cleaning solution which contains as thickener amine oxides. The solution further contains an acid salt or an acid which can be chloroacetic acid.
In DE-A-2,747,355, an antimicrobial composition is described which contains certain betaines, certain amine oxides and a protonating agent by which the pH is adjusted to between 4 and 5.5.
GB-B-1 4,494,109 teaches the composition of a bleaching surface-active composition which contains an addition product of H.sub.2 O.sub.2 with a tertiary amine oxide and a peroxide activator.